Gas pumping



Aug, 18 1942. J. JQWYDILER GAS PUMPING Filed April 11, 1940 2Sheets-Sheet l V I REVOLUTION R E m .m? W w N m N v M. VI H OB Q Au.f1s,"1942.

J J. WYDLER GAS PUMPING v 2. Sheets-Sheet 2 I Filed April 11, 1940 3 2-iNVENTOR JOHANN d. WY LER ATTOiQNEY Patented Aug. 18, 1942 UNITED STATS?TEN Fries GAS PUMPING sylvania Application April 11, 1940, Serial No.329,063

17 Claims.

This invention relates to gas pumping, and is particularly concernedwith improvements in method and apparatus for utilizing energy of gasesunder superatmospheric pressure for producing flow of and compressingother stationary bodies of gas under lower pressure.

A particular object of the invention is to provide improved method andmeans for utilizing the potential energy which is available in the hotwaste exhaust gases discharged from the cylinders of an internalcombustion engine for compressing and pumping air.

The present invention is directed to modifications of and improvementson the invention de scribed in my copending application Serial No.240,015, filed November 12, 1933, for Gas pumping, U. S. Patent No.2,234,100, issued March 4,

The gas exhaust period of the cycle of any four stroke cycle internalcombustion engine cylinder consists of two parts. During the first partof the exhaust period just after the exhaust valve has been opened, asubstantial proportion (roughly 50%) of the total weight of gas in thecylinder is rapidly discharged as a high pressure puff wave movingoutwardly from the cylinder into the exhaust manifold at relatively highinitial pressure and at high velocity. During the latter part of theexhaust period the remaining portion of the exhaust gases leaves thecylinder as a relatively low pressure wave moving in front of theadvancing piston, this period 'of the cylinder being referred to as thestroke period of the exhaust. During the stroke period of the exhaust,back pressure in the exhaust manifold may interfere markedly with themovement of the piston in the exhausting cylinder.

The operating cycle of the pump of the presen invention generallyfollows that of my aforesaid copending application, in that it includesfirst a displacement period during which a stationary body of air orother gas is trapped at atmospheric pressure within the pump while beingcompressed and then pushed out of the pump by pressure balancingdisplacement action of a flowing stream of gas under pressure, such ashot engine exhaust gases introduced into the pump during the puffdischarge period of a single engine cylinder exhaust cycle. Thisdisplacement period is followed by a scavenging period during which thepuff exhaust gases which have been trapped in the pump during thedisplacement operation are discharged from the pump and the pump isscavenged with air, preferably by means of energy derived at least inpart from the exhaust gases which are discharged from the same enginecylinder during the stroke period of the cylinder exhaust cycle. Airthus compressed and discharged from the pump by an operation derivingenergy from the hot gas pressure wave discharged from one cylinder of amulticylinder engine, may be delivered as supercharge air' to anotherengine cylinder having a coinciding air intake period.

The present invention provides that any assembly of gas pumping unitsand multi-cylinder four cycle engine should include a sufficient numberof engine exhaust manifolds to insure that the exhaust puff waves in anymanifold shall not follow each other at intervals shorterthan 180 enginecrank angle travel. Some of the pumps of the present invention, however,are so designed that they can be operated on a cycle which is completedwithin aperiod encompassed by crank angle travel of the engine supplyingthe exhaust gas for energizing the pump. Consequently a single pump maybe operated by the pressure waves occurring alternately in 'twoexhaustmanifolds of a six cylinder engine. Where the pump is also connected atits air discharge end with one or more air intake manifolds of theengine for the purpose of supplying compressed air to each enginecylinder during the last part of its air intake period, provision ismade for supplying air at atmospheric pressure to each engine cylinderduring the first part of its air intake period. Consequently the pumpneed only be of small capacity, and can be assembled in closely spacedrelation to the engine, with short air and gas transfer connections.

Another feature which differentiates the pump of the present inventionfrom that of my aforesaid copending application is in the use of alight, and in some designs, flexible sheet metal diaphragm or'floatingpiston mounted for reciprocal movement within the pump in response tosmall pressure difierentials applied to opposite faces thereof, andhaving low mechanical resistance or inertia to movement in eitherdirection. The diaphragm or piston serves to substantially inhibitcontamination of the air or other gas undergoing compression by theengine exhaust gas; insures more nearly perfect adiabatic compression byreducing transfer of heat; and affords more positive and efficientscavenging. The diaphragm or piston, therefore, is an importantcontributing factor in reducing the size of the pump or compressor to avolumetric capacity not substantially exceeding that of an enginecylinder, and in perlarly by reference to the accompanying draw- 1 ings,in which:

Fig. I is an assembly view, showing a single floating pistondisplacement pump operatively connected to exhaust and intake manifoldsof a six-cylinder four cycle internal combustion engine; the pump,engine intake and exhaust manifolds, and gas transfer connections andvalve chambers being shown in longitudinal section.

Fig. II is a pressure-time chart showing in full and dotted lines,respectively, the gas pressure waves which can be built up in two engineexhaust manifolds of a six-cylinder four cycle engine over a period of/2 engine cycle or one revolution.

Figs. III, IV, V and VI are cross-sectional views of the gas and airtransfer control valves taken respectively along the lines III-III,IVIV, VV and VIVI of Fig. I.

Fig. VII is another diagrammatic assembly view showing a single floatingdiaphragm displacement pump and the intake and exhaust manifolds of asix-cylinder, four cycle engine operatively connected by gas and airtransfer connections and transfer valves (parts being shown inlongitudinal section).

Fig. VIII is a View in vertical section of a modified form ofdisplacement pump equipped with a flexible diaphragm having its endsanchored to the pump housing.

Fig. IX is a plan view of the pump which is illustratedin Fig. VIII,taken on the line IXIX of Fig. VIII.

Fig. X is an assembly view of two floating piston displacement pumpsarranged in tandem and communicably connected respectively to two engineexhaust manifolds, together with gas and air transfer valves andconnections adapting the pumps for engine supercharging, parts beingshown in longitudinal section.

Fig. XI is a cross-sectional view of the apparatus of Fig. X, taken onthe line XI-XI of Fig. X.

Fig. XII is a cross-sectional view through one of the air transfervalves of Fig. X, taken along the line )flI-XII of Fig. X.

Figs. XIII, XIV and XV are cross-sectional views of the gas and airtransfer valves, taken respectively along the lines XIII-XIII, XIVXIV,and XV'XV of Fig. X.

Fig. XVI is a diagrammatic assembly view, chiefly in longitudinalsection, showing a pair of floating piston pumps mounted in tandem andeach communicably connected to individual engine exhaust and intakemanifolds, together with gas and air transfer connections and controlvalves.

Fig. XVII is a perspective view of a modified arrangement of two gasdisplacement pumps having rectangular pistons mounted on a commonoscillating shaft.

Fig. XVIII illustrates schematically an arrangement of two displacementpumps in tandem with connections to'separate engine exhaust manifolds,no hot gas transfer valves being provided.

In the apparatus assemblies which are illustrated in Figs. I, VII, X,XI, XVI and XVIII of the drawings, one or more displacement pumps 20 arearranged for the compression and pumping of air by means of energysupplied thereto from the hot exhaust gas-es discharged under lowsuperatmospheric pressure from a six cylinder four cycle internalcombustion engine 24. Within the pumps piston-like floating diaphragms22 are mounted to reciprocate with small clearance for the purpose ofpreventing substantial contact or intermixing between the compressinggas (exhaust gas) and the air or other gas being compressed, therebyinsuring eiiicient adiabatic compression. The air which is compressed inthe pump by a pressure balancing operation, is illustrated as beingutilized for supercharging the engine cylinders. However, as previouslyindicated, the invention is not limited to the use of engine exhaustgases as the energizing medium for the pump, nor to the compression ofair, nor to the use of such air for engine supercharging.

In Figs. I and VII, the cylinders of engine 24 have been numberedrespectively I, 2, 3, 4, 5 and 6; and cylinders i, 2 and 3 have beenshown with their exhaust ports connected through an exhaust manifold 26and passage 28 to housing 29 of a hot gas transfer control valve 3E1;while the exhaust ports of cylinders 4, 5 and 6 have been shown asconnected through exhaust manifold 32 and passage 34% to housing 35 of ahot gas transfer control valve 36. Likewise, the intake ports ofcylinders i, 2 and 3 have been shown as connected through an intakemanifold 33 and carburetor ii! to housing 4| of an air transfer controlvalve 42; while the intake ports of cylinders 4, 5 and 6 have been shownas connected through an intake manifold M and a carburetor liS tohousing M of an air transfer control valve 43. Hot valve housings 29 and35 are in turn connected to a hot gas intake and exhaust port 53 of pump20 by a forked transfer conduit 52; and cold valve housings ii and 4!are in turn connected to an air intake and ex haust port 54 of pump 2%)by a forked air transfer conduit 56. Concentric gas ejector nozzles 53and 69 are connected, respectively, to the housings 29 and 35 of the hotgas transfer control valves, and afford the means by which gas may bedischarged from either of the exhaust manifolds or from the pump toatmosphere by way of a Venturi throat 62 and muffler 64. An atmosphericair intake filter 66 is connected to housings ti and 41 of the airtransfer control valves in position to deliver air at atmosphericpressure to the pump and to either of the air intake manifolds andcarburetors.

The full line pressure time curve of Fig. II shows the successive steeppressure waves built up in an exhaust manifold (such as manifold 26) bythe exhaust gas discharges from two cylinders (for example cylinders iand 3) over one engine revolution. The exhaust of cylinder I beginsabout 45 crank angle before bottom dead center of crank I, producing astrong puff wave which builds up a peak and then subsides within aperiod of about crank angle, and is followed by a smooth weak strokeexhaust extending over about crank angle. The dotted line pressure timecurve of Fig. II shows the successive pressure waves built up in anotherexhaust manifold (such as manifold 32) by the exhaust gas dischargedfrom other engine cylinders (for example cylinders 4 and 5) at periodsshiftedin phase against the waves produced by gas discharges fromcylinders I and 3 by half of an exhaust period or by 120 crank anglefiring intervals. The puff discharge wave -of cylinder l occurssimultaneously with the stroke exhaust period of cylinder 4, and thepuff discharge wave developed in manifold 32 by cylinder 5 occurssimultaneously with the stroke exhaust wave of cylinder I in manifold26. The pressure waves as portrayed in Fig. II occur in an exhaustpiping system which is continuously open to atmospheric discharge. When,however, discharge of the exhaust gases to atmosphere is temporarilyblocked over the length of a cylinder puff discharge period, thepressure peak of the puff wave may be forced up higher and may bemaintained over a longer period. The subsiding side of the puff wave hasa slope and shape which depends on the rapidity with which the exhaustpiping system is reopened to free atmospheric discharge.

In the single floating piston type displacement pLunp-engine assemblieswhich are illustrated in Figs. I and VII, the puff discharge waves whichare produced successively by all six cylinders of engine 25, operatingwith crank angle spacings of 120, are all put to work within the samepump space in rapid succession, which means that the operating cycle ofthe pump must be completed within a time period corresponding to a 12iicrank angle movement of the engine.

The rotary gas and air transfer valves, arranged respectively betweenthe pump and the engine exhaust manifolds and between the pump and theengine intake system, are activated from the engine crank shaft in themanner illustrated by Fig. VII, the drive being taken for example bychain from the engine shaft to the shaft 12 on which valves 30 and 36are mounted and from shaft 12 to shaft 14 to which the air pressurevalves 42 and 48 are keyed. The valve actuating and timing mechanism isarranged for operating the respective valves at rates proportional tothe intervals between pressure peaks at the ,1

pulsating gas source of energy for operating the pump, namely in theengine exhaust manifolds.

In the operation of all six cylinder four cycle internal combustionengines, the cylinders each fire once during every two enginerevolutions, and the cylinders operate on cycles with a crank anglespacing of 126. Thus, while cylinder I is starting its gas exhaust,cylinder 6 is finishing its air intake; and while cylinder 4 is startingits gas exhaust, cylinder 3 air intake; and while cylinder 5 is startingits gas exhaust, cylinder 2 is finishing its air intake. In other words,the assemblies of displacement pumps and engine exhaust manifolds andintake manifolds as illustrated in Figs, I, VII, X and XVI are designedto pair the cylinders of the multi-cylinder internal combustion enginewhen utilizing energy supplied to the pump by the engine exhaust wavesfor supercharging the engine. energy carried by the exhaust gasdischarge from one cylinder of a pair can be utilized for compressingair and transferring such air as supercharge air into the other pairedcylinder during the last portion of its air intake period. During thefirst part of the air intake period of each cylinder, air can besupplied to the cylinder at atmospheric pressure. The pistons in eachcylinder of a pair, such as 2 and 5, pass simultaneously through theirtop and bottom is finishing its With the engine cylinders thus paired, 1

dead center positions. However, the power strokes of the pistons are 360crank angle apart in phase. In the case of engines having an unevennumber of cylinders, as for example nine cylinders, the dead centerpositions ofthe pistons in paired cylinders are not exactly together,for example 40 apart, and therefore the power strokes are apart in phaseless than 360, for example 320".

In the operation of the engine-displacement pump assemblies of Figs. Iand VII three cylinder discharge puif waves are supplied to the pumpfrom the engine discharge manifold system during each engine crank shaftrevolution. These gas discharge waves are designed to produce by meansof the pump three similar air compression waves in the engine intakemanifold system. The rising side of each exhaust puff wave measures theperiod during which the puff exhaust gas surges into the pump againstthe air, though separated from it by the diaphragm or floating piston,and during this period air is compressed in the pump and discharged fromthe pump to a transfer conduit. The receding side of the puff waverepresents the period during which exhaust gases are released from thepump to atmosphere and the period during which air rebounds from thetransfer conduit into the pump to fill it preliminary to a new operatingcycle. Thus one pump cycle may be said to be completed during the periodspanned between the two points a-c in the diagram of Fig. II.

The exhaust gas distributing valves 30 and 36 must operate on cycleswhich correspond with those of the pump, but also on cycles whichinclude the additional phase of passing the stroke exhaust from eachcylinder directly to the atmospheric discharge system 62 and 64 duringthe second half of each engine cylinder exhaust period. Likewise, eachof the air valves 42 and 433 must complete its cycle during the periodof the pump cycle, but has to accomplish the additional duty ofsupplying atmospheric air to the intake manifolds during the first partof the air intake period of each engine cylinder. The hot gas and coldgas transfer valves may be rotated at a speed 1 times the speed of theengine crank shaft, or at a straight fraction of such speed, for examplewith a speed crank shaft speed in the case where each of the valves isprovided with two opposite sets of ports, in place of the single portspossessed by the valves illustrated in Figs. I and VII. By providing thevalves with three sets of ports the speed of the valves may be reducedto the speed of .the crank shaft. With a single pump assembly the numberof strokes of the pump piston is always three times the number ofrevolutions of the crank shaft.

As shown in Figs. I, III and IV, each of the valves 30 and 36 is arotary tubular valve having a bore of annular cross section which opensat one end into the valve chamber and engine manifold connectedtherewith, and which is closed at the other end by a common cylindricalhub joining both valves to shaft 12. Each of the valves 35, 36 has asingle lateral port 25, 39 (Figs. III, IV) extending the full length ofthe valve wall and having a width subtending a cylinder arc ofapproximately Each of the air pressure valves 42 and 48 is a rotarycylinder segment subtending an arc of approximately 120 (Figs. V, VI).

Each of the hot gas transfer valves 30 and 35 performs three functionsduring one revolution.

During the first part of a cycle of pump 20, one of the valves rotatesto a position permitting passage of engine puff exhaust gases undersuperatmcspheric pressure into the pump from one exhaust manifold.During the second part of the pump cycle, the valve rotates further toopen the passage whereby puff exhaust gases trapped in the pump, exhaustmanifold, and exhausting cylinder, are released to atmosphere. Alsoduring this last part of the pump cycle and for some time after the pumpcycle is completed, the valve must cut off any further transfer ofexhaust gases to the pump and pass stroke exhaust gases from the sameengine manifold directly through the engine muffler system to theoutside atmosphere. In doing so the pump is disconnected from this sameexhaust manifold andenabled to perform another pumping cycle inconnection with another branch exhaust manifold.

Similarly, one of the air transfer valves 42 and 48 must operate duringthe first air displacement and compression period of each pump cycle totransfer compressed air from the pump space into the proper engineintake manifold. This period of communication between the pump and theintake manifold extends over all of the displacement and compressionperiod of the pump cycle and over a part of the air rebound period.After completion of the air rebound period, the air transfer valve mustoperate to admit scavenging air into the pump from atmosphere throughthe air filter fit. Simultaneously, with this scavenging air transferperiod, the air transfer valve must also operate to pass atmospheric airdirectly to one of the engine intake manifolds.

During the period when the one air transfer valve is in position to passcompressed air from the pump to one engine intake manifold, the otherair transfer valve must be closed to cut off additional parasitic spacesor escapes open to the outside and to prevent transfer of compressed airinto the other engine intake manifold. It will be noted that the periodin which intake of scavenging air to the pump takes place coincides fora short time with the period in which intake of atmospheric air takesplace to another of the cylinders beginning its intake period. Both ofthese atmospheric air intakes may be served by the same air transfervalve, or in part by both valves.

To some extent the valve timings of a particular pump design may differfrom those illustrated. However, the valve timings must always be suchas to avoid upsetting interference between the different pressure wavesby which the pump operates. Special attention must also be given todesigning the engine discharge system so as to prevent the building upof a back pressure in one of the two engine exhaust manifoldsparticularly during periods when puff waves are being transferred fromthe other manifold into the pump space. The concentric discharge nozzles58 and t and the expanding Venturi throat 62 have been provided for thespecific purpose of promoting rapid andpcw'erful scavenging of the pumpsystem while avoiding development of back pressure opposing the strokeexhausts.

The shafts 5-2 and M which, respectively, actuat the hot and cold gastransfer valves, are supported within the valve chambers by ballbearings The bearings supporting the shaft 12 for the hot gas transfervalves may be protected by water jackets 18 against excessive heat.Also, the hot valve shaft bearings may be protected against gas leakageby labyrinth gaskets 89 (Fig. I). The bearings for supporting the coldgas transfer valve shaft 14 may be protected against gas leakage by theusual type of bushings 19 with oil sealing, which has been found toprovide sufiicient tightness for cold gas pressures never fluctuatingbetween positive and negative pressure maxima of more than a few poundsper square inch.

Each of the hot gas and cold air transfer valves is shown in Figs. I,III, IV, V and VI, in the position which it assumes just prior totermination of the displacement compression operation period ab of Fig.II. During this period the hot puff exhaust gases from cylinder I andmanifold 26 are being transferred past valve 36 into pump 20.Simultaneously the valve 35 is in a position to transfer stroke exhaustgases from cylinder 4 and manifold 32 directly to atmosphere throughdischarge nozzle 6%! and funnel 64. At this same time compressed air isbeing transferred from the pump directly through valve 48, carbureter46, and air intake manifold 44, into cylinder 6. Also during thisperiod, air transfer valve 42 is in position for passing atmospheric airthrough carbureter ie and manifold 38 into cylinder 2.

The air compression chamber of pump 23 as viewed in Fig. I, always liesto the right of piston 22, and is of annular cross section surroundingthe stem of the piston. The volumetric displacement of the pump 2%,exclusive of the cubic displacement of the piston, which is relativelysmall, is never appreciably more than sufficient to handle the volume ofhot gas which is dis-charged from single engine cylinder during thefirst puff discharge period, and to compress only the air with which acylinder is supercharged at the end of its air intake period.

The atmospheric air intake ports under the control of air transfervalves 42 and 48 have been illustrated as by-passed, respectively, witha pair of air by pass conduits 34 and 8t. Valves 88 and 9% arerespectively mounted in conduits 84 and 86: and another valve 92 ismounted in the conduit 5% connecting the cold gas transfer valve housingwith the pump. Valves 88, 9E! and 92 afford the means whereby engine 24can be switched from normal operation to supercharging operation, orback to normal operation, at will. During supercharging, valves 58 and90 are closed and valve 92 is opened, as shown in Fig. 1. During normaloperation of the engine without supercharging, valve 92 is closed andvalves 8-8 and 98 are opened for passing atmospheric air directly andcontinuously from the air cleaner to the corresponding carbureters anden in intake manifolds.

The design of the pump-engine assembly illustrated in Fig. I is suchthat the displacement face of the pump piston is always exposed to theimpacts of the puff discharge waves from the engine cylinders. The wholesystem responds more rapidly to switching from atmospheric air intake tosupercharging when the hot gas side of the pump is continuouslysubjected to pulsating pressure. If, however, the operator desires toshield the pump during normal operation (without supercharging) againstthe hot pufi exhaust waves, a by-pass 9t may be provided leading fromeach of the engine exhaust manifolds directly into the muffler line(indicated in dotted lines in Fig. I), and special valves 95 may beprovided which on opening by-pass the exhaust puff waves directly intothe engine muflier.

The diaphragm of the pump illustrated in Fig.

VII has been shown as slidably journaled on a post 45 which is mountedon the main axis of the pump with its end supported by the end walls ofthe pump. A preferred design of the single diaphragm piston pump,however, has been shown in Fig. I, in which the piston 22 is attachedrigidly at its center to one end of a stem 23. The other end of stem 23carries a pin on which adjacent ends of two links 68 are pivotallyhinged. The opposite ends of links 68 in turn carry pins on which arerespectively hinged two oscillating rods 69. Rods 69 are in turnpivotally mounted on brackets attached to the casing of the pump. Theoscillating ends of rods 69, to which links 68 are respectivelyconnected, are connected togethor by a retractile spring Hi. Anoil-sealed stuifing box 2i is mounted in an aperture in the end plate ofthe pump within which stem 23 is reciprocably journaled.

During the compression period of each pump cycle all of the air which istrapped between the pump diaphragm and the air intake port of theintaking engine cylinder is subjected to compression by the fulldischarge gas wave. During the second half of the pump cycle, when thefull discharge wave is subsiding by reexpansion from the pump, theforces acting on the diaphragm to move it in the opposite directioninclude the suction developed in the Venturi exhaust orifice 62 by thestroke exhaust from one engine cylinder, and also the expansion force ofthe compressed air still trapped between the engine cylinder intakevalve which has just closed and the pump diaphragm. The pressure of theair thus trapped is rapidly reduced to atmospheric pressure by thecomplete expansion of the engine exhaust gases on the other side of thediaphragm, so that there is a tendency for the diaphragm movement toterminate somewhere in mid-stroke, without the aid of a device such asthe spring Til. The air pressure on the air side of the diaphragm israpidly reduced for another additional reason,

and that is that during the air rebound period of the diaphragm of thepumpsshown in Figs. I and VII, a second cylinder of the engine isbeginning its air intake period.

The spring 10 of the piston return mechanism illustrated in Fig. I hasbeen designed-as an energy absorbing element which converts tomechanical energy a small part of the energy imparted to the pistonduring the displacement period of the pump cycle, by building up tensionon the spring. The sprin need only be strong enough to absorb a verysmall proportion of the energy imparted to the piston. The constructionof the spring mechanism is such that the farther the piston moves towardthe right (as viewed in Fig. I) the smaller the amount of opposition tomovement of the piston. In other words, the spring has no efiectwhatsoever on movement of the piston at the time that the piston hasreached the position shown in Fig. I, that is, when the back pressure ofthe compressed air is greatest. However, the spring exerts its fullforce against the piston when the piston is near the end point of itstravel toward the extreme left hand position within the pump. The onlyforces bearing on the piston in the position shown in Fig. I are thebalancing gas pressures on opposite sides thereof. On release of thetrapped exhaust gases lying to the left of the piston at the end of thedisplacement compression period, the piston will start to movebackward'toward the left hand side of its path of travel, and thetension on the spring then comes into action to draw the oscillatingends of the links 69 toward each other, forcing the piston toward itsextreme left hand position and thereby producing air scavenging of thepump. During full speed operation of the piston, in a pump-engineassembly such as illustrated in Fig. I, the piston of the pump will nottravel the full length of its stroke, the length of the path of travelwhich it does traverse depending on the exact dynamics of the particularpump design and on the speed of the engine and pump.

The floating diaphragms of the pumps shown in Figs. I, VII, X and XVIare circular metal discs, while the diaphragms of the pumps illustratedin Figs. VIII, IX and XVII have a rectangular shape. In all cases thepump diaphragms are dimensioned to reciprocate within the pump housingswith a definite small clearance between the walls of the housing and theedges of the diaphragms. Very little leakage of gas occurs past thediaphragm through such small clearance space during the operation of thepump, since the gas pressure difierential between opposite faces of thediaphragm is always very small. In fact such pressure difierential isonly suflicient to overcome any inertia resistance of the floatingdiaphragm, which is kept as small as possible. The displacement pumpsare preferably designed with a large cross sectional area in comparisonwith the diaphragm stroke, for the.

purpose of reducing the diaphragm speed and the inertia forces operatingon the diaphragm to a minimum. This construction also has the effect ofmagnifying any motive force impresseo on the diaphragm and givinginstantaneous response of the diaphragm to any gas pressure differentialimpressed thereon.

In the pump modification which is illustrated in Figs, VIII and IX, thesheet metal diaphragm 11 has its ends rigidly attached to the shell ofthe pump and has sufiicient elasticity to provide for a self-flexingoperation between the full line position and the dotted line position.The method of suspending the ends of the diaphragm with respect to thepump housing of Figs. VIII and IX must be such as to allow for free playof the elastic self-retroactive properties of the diaphragm at anyinstant of the pump operating cycle.

In the double pump assembly which is illustrated in Fig. XVII, thefloating pistons of both pumps are flaps 9'! suspended on a commonoscillatory shaft 98. In this design, as in all double pump designs, theair and energizing gas in take and exhaust ports of the two pumps arearranged at opposite sides of the respective pump pistons in order thateach pump, when operating on the compression period of its cycle, willeffect automatic scavenging of the other pump during the scavengingperiod of its cycle. In the tandem pumps which are illustrated in Figs.X to XVI and XVIII, the energizing gas intake ports may be locatedeither at adjacent ends of the two pumps or at opposite side covers ofthe two pumps.

In the apparatus assemblies which are illustrated in Figs. X, XI, XVIand XVIII, two displacement pumps are mounted in tandem with theirfloating pistons connected by a common stem and interlocked forreciprocation in unison. The two pumps are designed for operation onalternate cycles, so that the displacement period in the operating cycleof one pump coincides with the air scavenging period in the cycle of theother pump, the interlocked piston functioning to make both thedisplacement and the scavenging entirely positive. Each pump isoperatively connected to only one of the two exhaust manifolds of thesix cylinder engine, so that each pump performs only half the number ofcycles that are required of the single pump in the assembliesillustrated by Figs. I and VII. In other words, each pump of the doublepump assemblies illustrated performs a number of cycles corresponding to1 /2 engine crank shaft speed (as compared to a pump cycle speed threetimes crank shaft speed for the single pump assembly of Figs. I andVII), and the gas and air transfer valves, when equipped withsingle-phased ports, also revolve at 1 engine crank shaft speed.

In the assemblies illustrated by Figs. X, XI and XVI and XVIII, exhaustmanifold 2t (for 0571111- ders i, 2 and 3) is in open and constantcommunication with one of the pumps 23 by means of a hot gas transferconduit 5|; while the other exhaust manifold 32 (for cylinders 4, 5 and6) is in open and constant communication with the other pump 20, bymeans of a separate hot gas transfer conduit 53. The floating pistons 22for the two pumps are preferably light alloy metal discs rigidly mountedon a common stem 61 which is, in turn, reciprocally supported bylubricated bushings and stuffing boxes 2| which are centrally mounted inthe end plates of each pump housing and are always cooled by air beingpumped. The working chambers of the two pumps shown in Figs. X, XI andmIII are disposed in tandem within a single housing, on opposite sidesof an inclined partition I03. In Fig. XVI, the two pumps are arranged intandem, each pump within its individual housing.

Manifold 25 is ported out (Figs. X, XI and XVI) at 2'! into the housingof a cylindrical gas discharge valve 3| and manifold 32 is similarlyported out at 33 into the housing of a cylindrical gas discharge valve31. Transfer conduits 5| and 53 are ported out into the respective pumpswith which they communicate at adjacent ends of the two pumps (Fig. XVI)or, in the case of Figs. X, XI and XVIII, at symmetrical points locatedat opposite sides of partition I55.

One engine intake manifold 38 (for cylinders l, 2 and 3) is shown asconnected through a carbureter 43 to the housing of a single-portedtubular air transfer control valve 43; while the other intake manifold44 (for cylinders 4-, 5 and 6) is connected through a carbureter 45 tothe housing of an air transfer control valve 49. The housings of valves43 and 49 are respectively connected to the respective displacementpumps 2!] by air transfer conduits 55 and 5'1. It will be noted that hotgas transfer conduits 5| and 53 are ported out into the respective pumps25, with which they communicate, at adjacent sides of the pump pistons22; and that the air or cold gas transfer conduits 55 and 51 are portedout into the respective pumps at the remote sides of the correspondingpump pistons.

Concentric gas ejector nozzles 65 and 58 are connected respectively tothe housing of hot gas discharge control valves 3| and 31 and afford themeans by which gas may be discharged from the exhaust manifolds, and thepumps connected therewith, to atmosphere by way of the Venturi throat 62and muflier 64.

' Each of the air transfer conduits 55 and 5'! is ported out into thecommon housing for a pair of air transfer control valves 63 and 65,which are single-ported tubular valves. Valves 63 and 65 are mounted torespectively control transfer of atmospheric air for scavenging thepumps from an air intake filter 55 to one of the conduits 5| and 55,while blocking transfer of atmospheric an to the other transfer conduit.

In the apparatus of Figs. X, XI, XII, XIV and conduits 55 and 51 areforked. The main forks of the respective conduits lead directly from thepumps to the corresponding atmospneric air control valves 63, 65. Theother forks 82 (of conduit 55) and 99 (of conduit 51) branch out of themain fork at points near the pump and lead up to the ports of transfervalve 43, 49.

A pair of air by-pass chambers 8| and 83 has been illustrated in Figs. Xand XVI. These bypass chambers are ported out at each side of air filter55. Communication between chamber 8| and intake manifold 38 is under thecontrol of valve while communication between chamber 33 and the intakemanifold 44 is under the con trol of valve 49. For supplying atmosphericair to the intake manifolds of the engine throughout the entire airintake period, in case pumps 20 are not operatively connected to deliversupercharge air during part of the intake period, by-pass pipes 85 and81 are provided, respectively con-' necting chambers 8| and 83 to theintake manifolds 38 and 44, bypassing valves 43 and 49. A butterflyvalve 89 is mounted in pipe 85, and a similar valve 9| is mounted inpipe 87. A valve 93 is mounted in fork B2 of the air transfer conduit 55(Fig. XV), and a similar valve 95 is mounted in fork 99 of air transferconduit 51 (Figs. X, XII). Valves 93 and 95 when closed block transferof compressed air from the pump to the engine intake manifolds. Valves89, 9|, 93 and S5 afford the means whereby the engine can be switchedfrom normal operation to supercharging operation, or back to normaloperation, at will. During supercharging, valves 89 and BI are closed,and valves 93 and 95 are open. During normal operation of the enginewithout supercharging, valves 93 and 95 are closed and valves 89 and 9|are open.

Hot gas transfer valves 3| and 3! (Figs. X, YI and XVI) are mounted on asingle drive shaft Likewise, air or cold gas control valves 43, 49, 63and 55 are all mounted on a single drive shaft 13. Shafts l'l and '53are operatively connected for actuating all of the hot gas and airtransfer con-, trol valves directly from the crank shaft of the internalcombustion engine. The shaft 1| for the hot gas valves is supportedwithin the valve chambers by ball bearings F5, and these ball bearingsare protected by water jackets 18 against excessive heat (Fig. X). Alsothe hot valve shaft bearings are protected against gas leakage bylabyrinth gaskets 8d. The bearings for supporting the air or cold gastransfer valve shaft 73 are protected against gas leakage by the usualtype of bushings E9 with oil sealing.

In the schematic assembly of two displacement pumps and six cylinderengine shown by Fig. XVIII, hot gas transfer control valves have beenomitted, and in place thereof there have been substituted a pair of gasejector nozzles 59 and 6| of predetermined restricted cross-section,which may be located in the same relative position as are the gasdischarge nozzles 53 and 60 of the assemblies portrayed in Figs. X, XIand XVI. The modified assembly, which is illustrated in Fig. XVIII, hasbeen particularly designed for operation at substantially constantspeed. The cross sectional area of each of the discharge nozzles 59 andEl is so chosen as to just handle the volume of gas discharged from anengine cylinder during the exhaust period without developing substantialback pressure during the stroke period of the exhaust. Consequently,because of the restricted area of these nozzles 59 and 6|, they have acon-' siderable blocking effect against the strong puff exhaust wavewhich exits from an engine cylinder during the first or puff period ofthe exhaust cycle. As a result of the partial blocking ffected bynozzles 59 and GI, a supercharging pressure of moderate intensity isimpressed on the piston of whichever one of the pumps is connected tothe manifold receiving that particular puff discharge wave. Thereduction in compression efiiciency or intensity which is obtained bythe design of v Fig. XVIII, in comparison with the assemblies of Figs.X, XI and XVI, may in some cases be justified by the greatersimplification of apparatus which result from the elimination of the hotgas transfer control valves.

Each of the hot gas and cold air transfer valves is shown in Figs. X toXV, inclusive, in the position which it assumes just prior totermination b of the displacement compression operation period a'b ofFig. II. During this period the hot puff exhaust gases from one of theengine cylinders, for example cylinder 6, are being transferred directlyfrom manifold into the pump 28 which is connected with that manifold.Simultaneously, valve 3? is in position to transfer stroke exhaust gasesfrom cylinder 4 and manifold 32 directly to atmosphere through dischargenozzle 58 and funnel (:22. At this same time, compressed air is beingtransferred from the chamber in the same pump at the opposite side ofthe piston directly past valve 49, carburetor 46 and air intake manifold34, into cylinder 8. Also during this period, air transfer valves t3 and65 are in position for passing atmospheric air from air cleaner 86through transfer conduit 55 into the air chamber side of the second pumpconnected with manifold 32 during the scavenging period of the cycle ofthis second pump.

Positive scavenging of thedisplacement pump with a fresh charge of airduring the last part of each pump cycle is assured by providing the pumppiston with a spring fly-wheel construction such as shown in Fig. I, orby connecting the piston with the piston of another pump (Figs. X, XI,XVI, XVII and XVIII) in such a manner that the first piston is moved ona suction stroke by the second piston operating on its displacementstroke. The discharge nozzles 58 and [ill are dis posed in concentricrelation at the entrance of the Venturi funnel 62 to assist scavengingof the pumps by applying the suction aspiration effect of a jet ofengine exhaust gases discharged directly from one engine exhaustmanifold to atmosphere through one of said nozzles during the strokeexhaust period of an engine cylinder connected to said manifold forpromoting development of suction in the pump connected to the otherexhaust nozzle during the scavenging period of the pump cycle. Anyinterference to pump scavenging which may be offered by air cleaner 66may be compensated by mounting a fan I02 (Figf XVI) at the entrance ofthe air cleaner to supply air thereto under slight pressure.

The invention having been thus described, what is claimed as new is:

1. In compressing and pumping air, the steps comprising movingcombustion gases under superatmospheric pressure in a confined stream inpressure waves following each other at substantially uniformly spacedrapidly repeated intervals, during an interval between successive wavepeaks trapping a body of air in a compression vessel at substantiallyatmospheric pressure, during the period of the next wave peakintroducing gas from said stream into one end of said vessel therebycompressing the air by a pressure balancing displacement operation,mechanically absorbing part of the energy carried into the vessel bysaid combustion gases, discharging the compressed air from the vesselwhile trapping the gas against escape therefrom and expanding the gastrapped therein to substantially atmospheric pressure, developing apartial vacuum by discharging gas from said stream directly toatmosphere in a high velocity expanding column during an intervalbetween wave peaks immediately following the displacement compressionstep, and utilizing a partial vacuum and mechanically absorbed energy toscavenge the vessel with a fresh supply of air at atmospheric pressurebefore repeating the cycle.

2. In gas pumping apparatus, a pump chamber, a diaphragm mounted withinsaid chamber for reciprocation therein in response to slight gaspressure differentials at opposite sides thereof, a source of fixed gasunder pulsating superatmospheric pressure, means permitting discharge ofgas directly from said source to atmosphere at a restricted rate, aconduit communicably connecting the pump at one side of said diaphragmwith said gas source, a branched conduit communicably connecting thepump at the opposite side of the diaphragm both to atmosphere and to acompressed air chamber, valve mechanism mounted for controlling supplyof atmospheric air to and 'delivery of compressed air from the pumpthrough the branched conduit, and valve actuating and timing means foroperating said valve mechanism at a rate proportional to the intervalbetween pressure peaks at the gas source.

3. Apparatus as defined in claim 2, in which the means permittingdischarge of gas from said source to atmosphere includes a valve, saidvalve being arranged for periodically interrupting communication betweensaid source and atmosphere. 4. In gas pumping apparatus, a pumpingvessel, a diaphragm mounted within said vessel for reciprocation thereinin response to slight gas pressure differentials at opposite sidesthereof, a source of fixed gas under pulsating superatmosphericpressure, a valve chamber having a valve mounted therein, a dischargenozzle leading off from said valve chamber to atmosphere, a conduitcommunicably connecting the pump at one side of said diaphragm with saidvalve chamber, a connection between the valve chamber and the gassource, said valve being arranged for periodically switchingcommunication between the gas source and pump and between the pump andatmosphere, a branched conduit communicably connecting the pump at theopposite side of the diaphragm to atmosphere and to a compressed airchamber, and valve mechanism mounted to control alternate supply ofatmospheric air to and delivery of compressed air from the pump throughthe branched conduit, together with valve actuating and timing means foroperating the respective valves at a rate proportional to the intervalbetween pressure peaks at the fixed gas source.

5. In gas pumping apparatus, a wall-enclosed one end thereof, a wastegas discharge conduitleading off from the gas source to atmosphere,valve mechanism arranged to control discharge of gas from the source andfrom the pump to atmosphere through the waste gas discharge conduits, aforked air transfer connection ported out of the pump through its otherend wall, and a pair of valves mounted to respectively controlintroduction of atmospheric air into and removal of compressed air fromthe pump through said air transfer connection.

6. A gas pump as defined in claim in which the valve mechanism which isarranged to control discharge of gas from the source and from the pumpto atmosphere is so positioned and arranged as to also control transferof gas between the source and the pump.

7. Apparatus as defined in claim 5 together with a second source offixed gas under pulsating pressure, branches of said gas transferconduit and waste gas discharge conduit respectively connecting saidsecond source with the pump and with atmosphere, and a pair of valvesmounted and arranged to respectively control transfer of gas betweeneach source and the pump and between the source and the pump andatmosphere.

8. Apparatus as defined in claim 5 in which the pump is cylindrical, andin which the diaphragm is a circular disc piston rigidly mounted on theend of a stem which is reciprocably journaled in an aperture in one endof the pump, together with a spring fiy wheel mechanism connected to thepiston stem in position tending to move the piston toward the gastransfer end of the pump during the air scavenging period of the pumpcycle.

9. In compressing and pumping air the steps comprising, producing flowof air from atmosphere in a confined stream, periodically introducingair at substantially atmospheric pressure into contact with one side ofa flexible diaphragm and trapping air thus introduced While increasingits pressure by movement of said diaphragm, thereafter releasing airthus compressed into said stream to increase the rate of flow in thedirection of stream flow, causing energy-supplying gas to flow undersuperatmospheric pressure in a confined path in pulsating pressurewaves, applying such gas pressure waves to the other side of saiddiaphragm to move the same and impart pressure energy therethrough totrapped air, mechanically absorbing and storing some of the energy thusimparted to the diaphragm, and between pressure waves expanding gas fromsaid gas stream to atmosphere and utilizing mechanically stored energyto assist return of the diaphragm to its original position.

10. An air compressing and pumping operation comprising setting up flowof air from atmosphere in a confined stream, introducing air atsubstantially atmospheric pressure into contact with one side of amovable partition and trapping air thus introduced While increasing itspressure by movement of said partition, thereafter releasing air thuscompressed into said stream to increase the rate of setting up flow of asecond stream of gaseous products of combustion under superatmosphericpressure in a confined path, contacting pressure gas from said secondstream with the other side of said partition thereby displacing the sameand imparting pressure energy therethrough to the trapped air,

, air

trapping the pressure gas in contact with the partition during thedisplacing and air release operations, and after each period ofcompressed release expanding gas from said second stream to atmosphereand returning the partition to substantially its original positionpreliminary to a new cycle.

11. A displacement pump comprising a wallenclosed housing of relativelylarge cross-section and short length, a diaphragm partition mountedtransversely in the housing between the ends thereof for reciprocationtherein in response to slight pressure difierentials between oppositesides thereof, a source of energy supplying fluid under pulsatingsuperatrnospheric pressure, a continuously open restricted outlet fromsaid source to atmosphere, a fluid transfer connection communicablyconnecting said fluid source and the interior of the pump housing at oneend thereof, connections for introducing a second fluid to be pumpedinto, and for removing said fluid from, the other end of the housing,and valve mechanism arranged to respectively control introduction offluid into, and removal from, the pump through said several connections.

.12. In compressing and pumping air the steps comprising setting up fiowof combustion gases under superatmospheric pressure in a confined streamin pressure waves following each other at substantially uniformly spacedrapidly repeated intervals, during an interval between successive wavepeaks trapping a body of air at one side at a diaphragm partition atsubstantially atmospheric pressure, during the period of the next wavepeak impressing said gas stream against the other side of said partitionthereby moving the partition ahead of the advancing gas wave andcompressing the air by pressure balancing displacement, mechanicallyabsorbing part of the energy imparted to the partition by saidcombustion gases, discharging the compressed air ahead of the advancingpartition, between wave peaks discharging gas from the gas side of thepartition to atmosphere to release pressure on the partition, andutilizing mechanically absorbed energy to assist in returning thepartition to its original position preparatory to a new cycle.

13. In compressing and pumping air the steps comprising, setting up flowof energy supplying gas in a confined stream from a source thereof underpulsating superatmospheric pressure, building up pressure waves in saidstream following each other with a frequency corresponding to thefrequency of the source pulsations, between wave peaks trapping air tobe compressed at low pressure in contact with one side of a movablediaphragm, impressing the following gas pressure wave against the otherside of the diaphragm thereby moving the diaphragm ahead of theadvancing gas wave and compressing the air by pressure balancingdisplacement, discharging air thus compressed ahead of the movingdiaphragm and between wave peaks discharging gas from the gas side ofthe diaphragm to atmosphere to thereby release pressure on thediaphragm, and returning the diaphragm to its original positionpreparatory to a new cycle.

14. The method which is defined in claim 13 in which the flow of energysupplying gas is directed to atmosphere through a back pressure buildingflow restriction.

15. The method of operation as defined in' claim 13 in which thecompressed air is disunder lower average perssure thereby building uppressure waves in said air stream of the same frequency andsubstantially the same magnitude as the pressure waves in the gasstream.

16. In gas pumping apparatus, a wall enclosed 5 pump housing ofrelatively large cross section and short length, a diaphragm partitionmovably mounted transversely in the housing for reciprocation therein inresponse to slight gas pressure differentials at opposite sides thereof,a 10 ing, valves arranged to control transfer of gas between the sourceand the pump and between the pump and the waste gas discharge conduit,valved connections for delivering atmospheric air to, and for removingcompressed air from, the pump at the other end thereof, and valveactuating and timing mechanism for operating the respective valves atrates proportional to the interval between pressure peaks at thepulsating pressure gas source.

17. Gas pumping apparatus as defined in claim 16 together with a secondsource of gas under pulsating pressure and a valve controlled connectionbetween said second gas source and the 15 pressure gas side of thehousing.

JOHANN J. WYDLER.

v CERTIFICATE OF CORRECTION. Patent No. 2,295,186. ugust 1 194.2.

JOHAN'N J'. WXDIER.

It is thereby eerti fied. that error appears in the printedspecifieationef the above numbered patent requiring eorrectionssfollows: Page 8, f1rst column, line 70,'befo,re "setting" insert theword and comma--f1ow,' and that the said Letters Patent should be readwith this correotion therein that the same m ayeonfomto the record ofthe case in the Patent Off1ce.:

Signed and sealed this 5rd day of November, A. D. 1914.2.

Henry Van Arsdale (Seal) Actihg Commissioner of "Patents'.

